Refractor



Sept. 27, 1932. j QNEIL 1,879,442

REFRACTOR Filed Feb. 27, 1952 Inventor: James A. QNeil;

by His Attorney.

Patented Sept. 27, 1932 UNITED STATES PATENT OFFICE 1 JAMES A. ONEIL, OF LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK REFRAGTOR 7 Application filed February 27, 1932. Serial No. 595,515;

The present invention relates to refractors such as are used with relatively large incandescent lamps, one application of such refractors being for street lighting.

In connection with the use of such refractors, it is customary to provide means for adjusting the lamp relatively to the refractor to obtain different desired light distributions and it is necessary, if the best results are to be obtained, that such adjustments be made accurately. Refractors are usually translucent and to enable such adjustments to be made, it is known to provide diametrically opposite transparent spaces in the refractor, termed usually peep-hole through which the filament may be viewed for adjustment. Such an arrangement is shown, for example, in the patent to Halvorson, No. 1,7 83,468, dated December 2, 1930. In connection with an ar-- rangement of this character, however, it has been found in practice that it is often not possible to obtain a distinct view of the filament and as a result, even when the opposed transparent peep-holes were provided, it was not possible sometimes to position accurately the lamp filament relatively to the refractor.

The object of the present invention is to provide an improved construction and arrangement of peep-holes whereby a distinct view of the filament may be obtained so that accurate adjustments of it may be made, and for a consideration of what I believe to be novel and my invention, attention is directed to the following specification and the claims appended thereto.

In the drawing, Fig. 1 is a perspective view partly in section of a refractor embodying my invention, a lamp being shown in connection with it; Fig. 2 is a detail face view of 4 one of the peep-holes; and Fig. 3 is a diagrammatic perspective View illustrating the operation of the device.

Referring to the drawing, the refractor comprises an outer wall 1 and an inner wall 2 which stand in spaced relation to each other and which may be formed of glass or other suitable material. Surfaces of the inner and outer walls are provided with prismatic light directing projections as is indicated at 3.

These prismatic projections render the refractor translucent. Theinner wall 2 is provided with a lower flange 4 on which the outer wall 1 rests and the two walls are fastened together at their upper ends by means of a sleeve 5 which projects through the opening at the top of the refractor and has a flange (not shown) which engages the inner surfaces of wall 2 and is held against it by a disk washer 6 which screws down on sleeve 5. This is a known refactor construction and is to be taken as typical of any refractor in connection with which it is dsired to provide peep-holes for use in adjusting the lamp filament.

According to my invention I provide opposed transparent sections 7 and 8 on the inner wall 2 in line with the desired range of filament adjustment. Extending transversely of sections 7 and 8 are lines 9 for use in leveling the eye with the refractor' and bringing the filament to the desired location. In outer wall 1 in line with sections 7 and 8, I provide on one side a transparent section 10 and on the other side an opaque or substantially opaque section 11. By the use of an opaque or substantially opaque section 11, I provide a background so that when viewing the filament through the sections 10, 9 and 8, it becomes clearly visible, enabling the filament to be accurately positioned. The section 11 may be rendered substantially opaque by etching the surface of the section or by other suitable means. By a substantially opaque section I mean a section which ofiers sufficient obstruction to the passage of light rays so that it forms a background for viewing the filament. In Figs. 1 and 3, 12 indicates a lamp filament. The respective surfaces 10, 9, 8 and 11 are made parallel or substantially parallel with each other so that there is no distortion of the filament when it is viewed through the peep-holes.

In the use of the invention, the operator views the filament through the peep-holes as indicated in Fig. 3, leveling the eye with the lines 9 in line with which it is desired to adjust the filament. Due to the background 11 the filament will be clearly visible and the lamp can be moved by the adjusting means provided to bring the filament to the desired position. 7 What I claim as new and desire to secure by Letters Patent of the United States, is: 6 1. A refractor comprising translucent walls, transparent portions in the walls on opposite sides of the refractor through which a filament may be viewed for adjustment, and means providing a substantially opaque 10 background in line with said transparent portions. A

2. A refractor comprising translucent walls, transparent portions in the walls on opposite sides of the refractorlthrough which 15 a filament may be viewed for adjustment, adjusting lines on said transparent portions, and means providing a substantially opaque background in line with said transparent portions; 20 In witness whereof I have hereunto set in han y JAMES A. ONEIL. 

